Manufacturing plants of the generic type, which are also called production lines, are general practice and known for example from DE 197 56 278 A1 or WO 02/00388 A1 or EP 1 084 794 A1; they comprise several side-by-side processing machines which workpieces are supplied to, and withdrawn from, via a conveyor and a delivery device that serves as a loader. These known manufacturing plants are constructionally very complicated.